The perennial forage peanut is a stoloniferous, perennial tropical legume with potential for use in pastures. Based on the hypothesis that under intermittent stocking herbage accumulation would follow a similar pattern to that described for tropical forage grasses, the objective of this study was to evaluate canopy characteristics and herbage accumulation of forage peanut subjected to strategies of rotational grazing management. Treatments corresponded to all possible combinations of two grazing frequencies (regrowth interrupted at 95% and maximum canopy light interception – LI95% and LIMax) and two grazing severities (post-grazing canopy heights (CHs) equivalent to 40 and 60% of the pre-grazing heights). Treatments were imposed to experimental units during an adaptation period (from November 2014 to January 2015) and the subsequent experimental period lasted from February 2015 to April 2016, comprising two consecutive pasture growing seasons with no interruption between them (summer I to summer II). The pre-grazing targets of LI95% and LIMax corresponded to CHs of 13 and 18 cm, respectively. Forage peanut showed high grazing tolerance as pre-grazing leaf area index (except during summer I and autumn/winter), total herbage, and leaflet dry matter accumulation varied only with seasons. Higher rates of herbage production were recorded during summer I and summer II, followed by those during late and early spring and autumn/winter. Since there was no difference in the pattern of herbage accumulation between LI95% and LIMax and stolons predominated at the bottom of the canopies, forage peanut may be rotationally grazed with greater flexibility than most tropical forage grasses. Recommended pre-grazing CHs are within 13 and 18 cm, and post-grazing heights between 40 and 60% of the pre-grazing height.

Currently, consumers are increasingly interested in obtaining high-quality and healthy lamb meat. Compared to grain-based diets, dietary forage legumes such as alfalfa and condensed tannin (CT)-rich sainfoin increase the levels of polyunsaturated fatty acids (PUFAs) that are beneficial for health in lamb meat thanks to their high content in PUFA and/or their impact on ruminal biohydrogenation. However, they can therefore adversely affect its oxidative stability. Thus, the impact of dietary forage legumes on lamb longissimus thoracis (LT) muscle FA composition and their stability to peroxidation was studied in 36 Romane lambs grazing alfalfa (AF; n = 12) or alfalfa plus daily supplementation with CT-rich sainfoin pellets (AS; n = 12; 15 g DM/kg BW, 42 g CT/kg DM) or stall-fed concentrate and grass hay indoors (SI; n = 12). Lambs were slaughtered at a mean age of 162 ± 8.0 days after an average experimental period of 101 ± 8.1 days. Forage legumes-grazing lambs outperformed SI lambs in LT nutritional quality, with more conjugated linoleic acids and n-3 PUFAs, especially 18:3n-3, eicosapentaenoic and docosahexaenoic acids (P < 0.001), and thus lower n-6 PUFA/n-3 PUFA and 18:2 n-6/18:3 n-3 ratios (P < 0.001). Peroxidizability index was higher (P < 0.001) in LT muscle of forage legumes-grazing lambs. Concurrently, two endogenous antioxidant enzyme activities, superoxide dismutase and glutathione peroxidase, were, respectively, similar and lower (P < 0.001) for forage legumes-grazing compared with SI lambs. A lower vitamin E level in SI lambs compared with forage legumes-grazing lambs (1.0 v. 3.8 mg/g, P < 0.001) could explain that malondialdehyde content, a marker of lipid oxidation intensity, was 0.63 µg/g in SI after 8 days in aerobic packaging conditions, whereas it remaining steady at 0.16 µg/g in forage legumes-grazing lambs. Dietary forage alfalfa thus improved FA composition of lamb LT muscle and their stability to oxidation when compared to SI lambs. However, supplementation of alfalfa-grazing lambs with CT-rich sainfoin pellets did not affect the nutritional quality of LT muscle FAs.

Polyphenol oxidase (PPO) in red clover (RC) has been shown to reduce both lipolysis and proteolysis in silo and implicated (in vitro) in the rumen. However, all in vivo comparisons have compared RC with other forages, typically with lower levels of PPO, which brings in other confounding factors as to the cause for the greater protection of dietary nitrogen (N) and C18 polyunsaturated fatty acids (PUFA) on RC silage. This study compared two RC silages which when ensiled had contrasting PPO activities (RC+ and RC−) against a control of perennial ryegrass silage (PRG) to ascertain the effect of PPO activity on dietary N digestibility and PUFA biohydrogenation. Two studies were performed the first to investigate rumen and duodenal flow with six Hereford×Friesian steers, prepared with rumen and duodenal cannulae, and the second investigating whole tract N balance using six Holstein-Friesian non-lactating dairy cows. All diets were offered at a restricted level based on animal live weight with each experiment consisting of two 3×3 Latin squares using big bale silages ensiled in 2010 and 2011, respectively. For the first experiment digesta flow at the duodenum was estimated using a dual-phase marker system with ytterbium acetate and chromium ethylenediaminetetraacetic acid as particulate and liquid phase markers, respectively. Total N intake was higher on the RC silages in both experiments and higher on RC− than RC+. Rumen ammonia-N reflected intake with ammonia-N per unit of N intake lower on RC+ than RC−. Microbial N duodenal flow was comparable across all silage diets with non-microbial N higher on RC than the PRG with no difference between RC+ and RC−, even when reported on a N intake basis. C18 PUFA biohydrogenation was lower on RC silage diets than PRG but with no difference between RC+ and RC−. The N balance trial showed a greater retention of N on RC+ over RC−; however, this response is likely related to the difference in N intake over any PPO driven protection. The lack of difference between RC silages, despite contrasting levels of PPO, may reflect a similar level of protein-bound-phenol complexing determined in each RC silage. Previously this complexing has been associated with PPOs protection mechanism; however, this study has shown that protection is not related to total PPO activity.

Cell suspension cultures of white clover (Trifolium repens L. ‘Regal Ladino’) were treated with 2,4-D [(2,4-dichlorophenoxy)acetic acid], 2,4-DB [4-(2,4-dichlorophenoxy)butyric acid], 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid], 2,4,5-TP [2-(2,4,5-trichlorophenoxy) propionic acid], and 2,4,5-TB [4-(2,4,5-trichlorophenoxy)butyric acid]. Cell population densities were monitored throughout the treatment period and herbicide remaining in the cells and culture medium was extracted and quantified at the termination of the treatment. Herbicide tolerance increased in cell populations which were conditioned by pretreatment with 2,4-DB and 2,4,5-T. However, 2,4-DB was rapidly degraded by all cell populations regardless of pretreatment. White clover cell suspension cultures treated with 2,4-D, 2,4-DB, 2,4,5-T, 2,4,5-TP and 2,4,5-TB metabolized the homologs, according to the following sequence: butyric acidåpropionic acidåacetic acid homologs. There was no difference in the rate of degradation of similar homologs of the 2,4-dichloro- and 2,4,5-trichloro- analogs.

The silvopastoral system (SPS) has been suggested to ensure sustainability in animal production systems in tropical ecosystems. The objective of this study was to evaluate pasture characteristics, herbage intake, grazing activity and milk yield of Holstein×Zebu cows managed in two grazing systems (treatments): SPS dominated by a graminaceous forage (Brachiaria decumbens) intercropped with different leguminous herbaceous forages (Stylosanthes spp., Pueraria phaseoloides and Calopogonium mucunoides) and legume trees (Acacia mangium, Gliricidia sepium and Leucaena leucocephala), and open pasture (OP) of B. decumbens intercropped only with Stylosanthes spp. Pastures were managed according to the rules for organic cattle production. The study was carried out by following a switch back format with 12 cows, 6 for each treatment, over 3 experimental years. Herbage mass was similar (P>0.05) for both treatments, supporting an average stocking rate of 1.23 AU/ha. Daily dry matter intake did not vary (P>0.05) between treatments (average of 11.3±1.02 kg/cow per day, corresponding to 2.23±0.2% BW). Milk yield was higher (P<0.05; 10.4±0.06 kg/cow per day) in the SPS than in the OP (9.5±0.06 kg/cow per day) during the 1st year, but did not significantly differ (P>0.05) in subsequent years. The highest (P<0.05) values for herbage mass and milk yield were observed during the 3rd year. In the SPS, with moderate shade (19% shade relative to a full-sun condition), the grass CP was higher (P<0.05) than in the OP, although the NDF content and digestibility coefficient were not modified. The animals spent more time (P<0.05) idling in the SPS than in OP. The higher legume proportion in the SPS was associated with the higher CP level in B. decumbens relative to the OP, which could explain the better (P<0.05) performance of the cows in silvopastoral areas during the 1st year. However, during the 2nd and 3rd years, similarities in the legume percentages of both systems resulted in similar (P>0.05) milk yields. Low persistence of Stylosanthes guianensis was observed over the experimental period, indicating that the persistence of forage legumes under grazing could be improved using adapted cultivars that have higher annual seed production. The SPS and a diversified botanical composition of the pasture using legume species mixed with grasses are recommended for organic milk production.

Cropping systems that include forage legumes and small grains in addition to corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] can achieve similar or higher crop productivity and economic return than simpler corn–soybean rotations. We hypothesized that this rotation effect occurs regardless of the crop genotype planted and the herbicide and cultivation regime selected for weed management. To test this hypothesis, we conducted a 3-year experiment that compared three cropping systems: a conventional 2-year corn–soybean rotation, a 3-year corn–soybean–oat (Avena sativa L.)/red clover (Trifolium pretense L.) rotation, and a 4-year corn–soybean–oat/alfalfa–alfalfa (Medicago sativa L.) rotation. Within each cropping system, two contrasting sets of management strategies were used: (i) genetically engineered corn with resistance to insect pests (Ostrinia nubilalis Hübner and Diabrotica spp.) plus the broadcast application of pre-emergence herbicides, followed in the rotation by a genetically engineered soybean variety with resistance to the herbicide glyphosate plus the post-emergence broadcast application of glyphosate; and (ii) non-genetically engineered corn plus the banded application of post-emergence herbicides, followed in the rotation by a non-genetically engineered soybean and banded application of several post-emergence herbicides. The two management strategies were identified as ‘GE’ and ‘non-GE.’ Corn yield was higher in the 3-year (12.51Mgha−1) and 4-year (12.79Mgha−1) rotations than in the conventional 2-year (12.16Mgha−1) rotation, and was also 2% higher with the GE strategy than with the non-GE strategy. Soybean yield was similar among rotation systems in 2008, but higher in the 3- and 4-year systems than the 2-year rotation in 2009 and 2010. Soybean yield was similar between management strategies in 2008, but higher in the GE strategy in 2009, and similar between strategies in the 3- and 4-year rotations in 2010. Increases in rotation length were accompanied by 88–91% reductions in synthetic N fertilizer application, and the use of the non-GE rather than the GE strategy was accompanied by a 93% reduction in herbicide active ingredients applied. Averaged over the period of 2008–2010, net returns to land and labor were highest for the 3-year rotation managed with either the GE ($928ha−1yr−1) or non-GE ($936ha−1yr−1) strategies, least in the 2-year rotation managed with the non-GE strategy ($738ha−1yr−1), and intermediate in the other rotation×management combinations. Our results indicate that more diverse crop rotation systems can be as profitable as conventional corn–soybean systems and can provide farmers with greater flexibility in crop management options.

Among the forage legumes somatic embryogenesis has been most studied in alfalfa (Medicago sativa L.) reflecting inherent breeding problems and the high demand for seeds of this species. Current methods of somatic embryogenesis are reviewed with emphasis on each of the 3 stages involved: the acquisition of competence, the induction of somatic embryogenesis, and somatic embryo development and maturation. The role of plant growth regulators is particularly stressed. Artificial seed production, the development of reduced-generation synthetics or hybrids and genetic transformation of alfalfa are considered. Research on somatic embryogenesis and plant transformation in a wide range of other forage legumes is examined but it is suggested that the application of artificial seed technology is unlikely in forage legumes other than alfalfa.

UK agriculture is undergoing significant change with reduced subsidies for food production, increasing consumer demands for food safety and traceability, and environmental concerns including climate and demographic change. The International Treaty on Plant Genetic Resources for Food and Agriculture adopted by the United Nations Food and Agriculture Organisation supports the use of genetic resources for research and breeding. Mining genetic resources for useful genetic variation is perceived as a major benefit of genebanks. However, utilization by breeders may be constrained by poor characterization of genetic resources, a widening gap between improved and unimproved material, and the disruption of well- adapted genotypes during introgression. Breeders working with grasses and forage legumes for sustainable agriculture are fortunate in the wealth of genetic variation available both within the primary species of interest and among related species. New DNA technologies allow more targeted approaches to the use of these genetic resources. Possibilities for gene transfer between related species using conventional techniques expand the available gene pools while potential use of genetic transformation extend these even further.

Farming systems are often complex elaborations of the human societies to which they belong, with many traditional and social implications. Untangling the main social and structural constraints may improve productivity without an increase in environmental costs. Integration of cereal and sheep farming throughout the Mediterranean basin has been traditional. Mutually beneficial relationships between the sheep industry and cereal farming, and the vital role of forage legumes in meeting the modest needs of sheep for nitrogen, are stressed. This agropastoral system, however, is endangered in central Spain mainly because the pastoralist (sheep owner) is land-less, while the cultivator (land owner) has little interest in enforcing the law; fees for grazing rights are very low. Farmers, particularly young farmers, reject the current sheep operation because of the harsh working conditions. Restructuring of the grazing system would require a new policy scenario that would link European Union farm subsidies to structural reforms and would stress cooperative behavior.